Software is being developed for a PET scanner which is being constructed by the Neuroradiology and Computed Tomography Section. The picture processing program is being optimized for speed and accuracy. This involves the use of low level languages and intimate knowledge of image processing mathematics and the computer architecture. Substantial improvements in execution time have been achieved. A study is under way to determine if the addition of any array processor to the PET computer would improve times by amount sufficient to justify its purchase.